I finished one of my projects last night. That was a good feeling.
I heard a seminar speaker once who said to keep a 'Win' box. Whenever something good was completed, you received a special card from a loved one, a letter of recognition, put it in the 'Win' box. Then, when you're feeling like life has worked you over, go pick up that 'Win' box and go through some of the things you have put there. It will show you that you do have value, that you do have people who care, and that you have just forgotten the many blessings you have been given.